Conventionally, a high-pressure pump is widely known that is used for an internal-combustion engine of a direct-injection type, and the like, and that pumps fuel to fuel-injection valves. For example, Patent Literature 1 discloses a high-pressure pump which includes a rocker arm rocking in association with a rotation of a cam of the internal-combustion engine, a pivot supporting the rocker arm in a rockable manner, and a plunger reciprocating in association with a movement of the rocker arm.
The rocker arm provided in the high-pressure pump as mentioned above includes a roller rotating on the axis thereof parallel to a cam shaft of the internal-combustion engine. The rocker arm has a first end protruding from the part thereof to which the roller is attached, and a second end protruding from the part thereof to which the roller is attached in a direction opposite to the first end. The rocker arm is provided on the top of the cam of the internal-combustion engine so that the roller comes in contact with the outer circumferential surface of the cam in a state where the pivot is arranged in a semispherical recess formed on the top surface of the second end, and where the plunger comes in contact with the top surface of the first end.
The rocker arm configured in this manner is mounted as follows.
First, the rocker arm is arranged on the top of the cam of the internal-combustion engine so that the roller of the rocker arm comes in contact with the outer circumferential surface of the cam, and the pivot is arranged in the recess of the second end of the rocker arm.
Then, the plunger is brought into contact with the first end of the rocker arm.
When the rocker arm is provided on the top of the cam of the internal-combustion engine as mentioned above, the rocker arm tilts around the roller under the weight thereof so that the second end moves downward, and finally may fall down from the cam.
Consequently, when, for example, the high-pressure pump is installed in the internal-combustion engine in a manufacturing line, or the high-pressure pump is replaced, these operations are complicated.